Managing the aural characteristics (the combination of the all of the acoustically radiating sources) of an aircraft is important in many environments. Minimizing annoyance to passengers and people on the ground (known as noise pollution) is important to civil applications, while avoiding detection is important to military aircraft utility. Indeed, noise pollution, and the desire to control (or reduce) it, has resulted in significant regulation preventing or otherwise inhibiting, operation of aircraft in close proximity to people and/or residential areas. Furthermore, this acoustic radiation has significant directionality and can propagate long distances. Beyond nuisance, high-intensity noise produced in certain applications can pose a health risk and can even pose a risk to nearby materials' structural integrity.
Rotor-driven aircraft are particularly prone to generate acoustic radiation, where the aircraft's rotors/propellers are a dominant source of acoustic radiation. Accordingly, acoustic radiation emitted by propellers/fans/rotors is an undesirable byproduct of their primary function—to generate thrust/propulsion. In view of the foregoing, a need exists for a system and method for controlling the acoustic radiation emitted by an aircraft, such as the aircraft's propellers, fans, and/or rotors.